SpinButton with float value

[Angel Jimenez Jimenez <ajimenez vnet es>]

Hi.

 I'm trying to use a spin button to edit a float value, but I can't get
it to work. All I can enter is an integral positive number. I'm probably
doing something wrong, but I can't figure out what.

 This is the code (using GTK--):

   ptAdjustment = new Gtk_Adjustment (value, FLT_MIN, FLT_MAX, 1, 10,
10);
   assert ( ptAdjustment );

   ptWidget = new Gtk_SpinButton (ptAdjustment, 0, 3);
   assert ( ptWidget );

 Thanks.
 Angel.